21202011211 has 4 divisors (see below), whose sum is σ = 21206535624. Its totient is φ = 21197486800.

The previous prime is 21202011199. The next prime is 21202011241. The reversal of 21202011211 is 11211020212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21202011211 - 2¹¹ = 21202009163 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202011191 and 21202011200.

It is not an unprimeable number, because it can be changed into a prime (21202011241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2255170 + ... + 2264551.

It is an arithmetic number, because the mean of its divisors is an integer number (5301633906).

Almost surely, 2^21202011211 is an apocalyptic number.

21202011211 is a deficient number, since it is larger than the sum of its proper divisors (4524413).

21202011211 is an equidigital number, since it uses as much as digits as its factorization.

21202011211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4524412.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21202011211 its reverse (11211020212), we get a palindrome (32413031423).

Subtracting from 21202011211 its reverse (11211020212), we obtain a palindrome (9990990999).

The spelling of 21202011211 in words is "twenty-one billion, two hundred two million, eleven thousand, two hundred eleven".